The present invention is generally directed to process measurement systems used in the mineral, chemical and food processing industries, and in particular to an apparatus for clearing process tapping points.
The processing industry relies upon the accurate measurement of process variables to enable the optimal control of their refining or manufacturing processes. One of the most common methods of taking various process measurements is via process tapping points exposed to the interior contents of a process vessel or pipeline.
Such tapping points encounter progressive scaling or debris build-up over time within their internal bore. The restriction or blockage of process tapping points by scaling or debris build-up can cause inaccurate process measurement, inaccurate product sampling or even render the process measurement completely unavailable.
Therefore, when process tapping points are blocked or restricted to the point of affecting the accuracy of the process measurement, they need to be cleared.
Current method for the clearance of process tapping points includes the manual removal of the blocking material using manual or power tools whilst the process is online. This can however be a highly hazardous operation for even the most experienced operators. This is because of the hazardous nature of most process fluids.
Another method used to maintain the clearance of the process tapping points is the introduction of a purge fluid through the tapping points. This purge fluid passes continuously through the tapping point keeping it clear of any scaling or debris. The disadvantage of this method is that it adds a large amount of inert media to the process fluid that must later be extracted at significant expense to maintain process efficiency. Further, the introduction of purge fluid through the tapping point does not stop the tapping point blocking, but merely delays the blocking. Thus another way of preventing the blockage is to provide larger diameter tapping points so that the time taken to block is longer.
Large oversize process connections have also been utilised to provide for longer periods where accurate process measurements can be obtained. This arrangement however merely delays the inevitable need to clear the process tapping points. Oversize process connections are also more expensive to install than conventional connections.
Although described with reference to process industry it would be clear to a person skilled in the art that the present invention has applicability to a number of industries where access is required to a pipe or vessel that scales during use.